1.Technical Field
The present invention relates to a license-supply technique.
2.Background Art
Information that specifies the use of a content includes two types of information. One type of information (hereinafter referred to as content management information) is supplied to an apparatus with the content when the content is supplied to the apparatus. The other type of information (hereinafter referred to as license information) is purchased by a user who has received the supply of the content. The license-supply technique is a technique to supply the latter-mentioned license information to a user.
For example, assume that the copy of the content is not permitted by the content management information that is supplied to a user with the content. In a case where the user desires to copy the content, the user can copy the content by purchasing, on a subsequent day, the license information that specifies “a permitted number of times of copying is once”.
Techniques for copying a content according to the content management information include a technique described in the following Patent Document 1. This known technique described in Patent Document 1 includes a method to analyze the content management information. When a content stored in an HD drive is to be copied on a DVD, copy information is analyzed first. Then, the result of the analysis determines, for example, whether to permit copying of the content, or to prohibit the copying while permitting only to move the content.
Also, techniques for restricting the reading of a content according to the content management information include a technique described in the following Patent Document 2. In this known technique described in Patent Document 2, when a content is to be recorded onto an external recording medium, the phone number of a mobile phone is also recorded thereto in connection with the content. This enables the content to be read only when a phone number matches with the phone number of the mobile phone.    [Patent Document 1] Japanese Laid-Open Patent Application No. 2003-22610; and    [Patent Document 2] Japanese Patent Publication No. 3416621.
However, in the conventional technologies described above, the content management information is added to a content and written to a recording medium when the content is to be recorded. Therefore, what type of operation can be performed on the content, and in what kind of environment the content can be used, are permanently determined by the description of the content management information recorded on the recording medium together with the content. Therefore, the type of permitted operation and the kind of environment in which the content is permitted to be read cannot be changed after the content management information is recorded onto the recording medium, resulting in causing inconvenience to the user.
Here, if a user purchases the above-described license, the range of permitted operations can be increased to some degree. However, even though the user purchases such a license, the environment in which a content is permitted to be read cannot be changed after the content management information is recorded onto the recording medium, which has been inconvenient to the user.
Such restrictions to the reading environment may be caused by an encryption method used when storing the content management information and the license information. Generally, the content management information and the license information are encrypted with use of an identification unique to an apparatus, and an identification unique to a recording medium. As a result, the content management information and the license information become unique to the specific apparatus and the specific recording medium, and cannot be used for any other apparatus and recording medium but the specific apparatus and recording medium.
Because of such restrictions on the recording medium and the apparatus, which are caused by the encryption method, even though a single person desires to use the content with an apparatus other than the specific apparatus, or a plurality of persons who belong to a particular organization desire to use the content together, these demands cannot be satisfied. In conventional technologies, a place to use the content is restricted to an apparatus having the acquired content management information or the license information, which lacks in convenience.
The object of the present invention is to provide a recording/reproducing device that favorably changes an entity that uses a content, and a place where the content is permitted to be used.